Terrified Afghans are fleeing in case the US attacks
A leading figure in Afghanistan's anti-Taleban opposition, Gulbuddin Hekmatyar, has said the Americans are wrong to blame Osama Bin Laden for the attacks in New York and Washington.
Speaking to the BBC, Mr Hekmatyar said the Americans had no right to attack Afghanistan.
Mr Hekmatyar and his Hizb-e Eslami party were major players in the struggle to end the Soviet occupation of the country and in the subsequent power struggle between rival Afghan factions before the Taleban practically swept the board in the mid-1990s.
Since then he has been based in Iran, though he retains some pockets of influence in northern Afghanistan.
National loyalty first
But now, far from cheering the Americans on against the Taleban, he says Washington is making a big mistake.
Mr Hekmatyar said he had no reason not to believe Bin Laden's denial of involvement in the New York and Washington attacks.
He said the Americans had no justification for an attack on Afghanistan in which the Afghan people would be the victims.
He made it clear that if the Americans staged an invasion and tried to install a friendly regime, his and other groups would return to Afghanistan and oppose them.
New unity
"I think if Afghanistan is attacked by America, then our nation has no other choice but to defend their country... The whole of our nation will stand against the attack on their country and... we will go and join our nation," Mr Hekmatyar said.
The Afghan opposition is notoriously fragmented.
But Mr Hekmatyar said that if the Americans staged a major operation, as he believed they would, they would succeed in uniting the Afghan factions against them in the same way as the Soviets did.
And he believed that the US would be no more successful than the Soviets were in imposing their will on the country.
If nothing else, Mr Hekmatyar's warning served as a reminder of the dangerous vacuum and likely chaos that would ensue if the Taleban regime were to be driven out.